database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-29 10:41:53 +03:00
Code Activity

Add code to prevent transaction ID wraparound by enforcing a safe limit

Browse Source 
in GetNewTransactionId().  Since the limit value has to be computed
before we run any real transactions, this requires adding code to database
startup to scan pg_database and determine the oldest datfrozenxid.
This can conveniently be combined with the first stage of an attack on
the problem that the 'flat file' copies of pg_shadow and pg_group are
not properly updated during WAL recovery.  The code I've added to
startup resides in a new file src/backend/utils/init/flatfiles.c, and
it is responsible for rewriting the flat files as well as initializing
the XID wraparound limit value.  This will eventually allow us to get
rid of GetRawDatabaseInfo too, but we'll need an initdb so we can add
a trigger to pg_database.
This commit is contained in:
Tom Lane
2005-02-20 02:22:07 +00:00
parent 617d16f4ff
commit 60b2444cc3
15 changed files with 1191 additions and 571 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
src/backend/bootstrap/bootstrap.c
View File

@ -8,7 +8,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/bootstrap/bootstrap.c,v 1.198 2005/01/14 21:08:44 tgl Exp $
* $PostgreSQL: pgsql/src/backend/bootstrap/bootstrap.c,v 1.199 2005/02/20 02:21:31 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -39,6 +39,7 @@
#include "storage/proc.h"
#include "tcop/tcopprot.h"
#include "utils/builtins.h"
#include "utils/flatfiles.h"
#include "utils/fmgroids.h"
#include "utils/guc.h"
#include "utils/lsyscache.h"
@ -407,6 +408,7 @@ BootstrapMain(int argc, char *argv[])
bootstrap_signals();
StartupXLOG();
LoadFreeSpaceMap();
BuildFlatFiles(false);
proc_exit(0); /* startup done */
case BS_XLOG_BGWRITER: